CN101650610A

CN101650610A - Optical touch-control pen and optical touch screen for mobile terminal

Info

Publication number: CN101650610A
Application number: CN200910172018A
Authority: CN
Inventors: 范富诚
Original assignee: AU Optronics Corp
Current assignee: AU Optronics Corp
Priority date: 2009-09-03
Filing date: 2009-09-03
Publication date: 2010-02-17

Abstract

The invention provides an optical touch-control pen for a mobile terminal, wherein the optical touch-control pen has a fluorescent substance and uses the fluorescent substance to convert part of an infrared source into visible light. The invention also provides an optical touch screen; when the optical touch-control pen contacts the optical touch screen, the optical touch-control pen uses the fluorescent substance to convert part of the infrared source into visible light, and the optical touch screen detects infrared light and visible light to locate the contact position of the optical touch-control pen. Since the optical touch-control pen and the optical touch screen use the fluorescent material to convert part of the infrared source into visible light, users do not need to provide powersupplies for the optical touch-control pen; in addition, an optical sensor or a camera installed in the optical touch-control pen also provides a quicker realizing method for the accurate locating ofthe touch-control pen.

Description

Optical touch pen and optical touch screen for mobile terminal

Technical Field

The invention relates to a liquid crystal display screen of a mobile terminal, in particular to an accurate positioning technology of the liquid crystal display screen based on an optical touch pen.

Background

With the rapid development of mobile communication technology, more and more mobile phones provide more friendly man-machine interaction mechanisms, such as a handwriting pad, a touch screen and a touch pen. When a user uses the handwriting board, the method is faster compared with a key input method; when a user uses the touch pen and the liquid crystal display screen with the touch control function, the user can quickly find out the expected function menu and interface, and the complicated process of searching the menu layer by using the keys is avoided. In addition, for the mechanical keys, the use of the touch pen does not affect the normal functions of the mobile phone.

However, the prior art stylus also brings some trouble to the user. For example, when a user logs on a network, a local area on the display screen may contain a lot of information, and when a certain piece of information is clicked exactly, the location of the stylus is not very accurate. In addition, current touch pens typically provide a point source of light at the tip of the pen to better locate a specific area or point. However, the use of point light sources may increase the power supply or the battery.

Disclosure of Invention

Aiming at the defects of the stylus in the prior art during accurate positioning, the invention provides an optical stylus and an optical touch screen for a mobile terminal.

According to an aspect of the present invention, there is provided an optical stylus for a mobile terminal, wherein the optical stylus has a fluorescent substance by which a portion of light of an infrared light source is converted into visible light.

Preferably, the infrared light source is an LED light source. And the light emitted by the LED light source is directly emitted to the optical touch pen or is transmitted in the waveguide tube.

Preferably, the camera receives infrared light and visible light to locate the position of the optical stylus in the display area.

According to still another aspect of the present invention, there is provided an optical touch screen for a mobile terminal, wherein when an optical stylus is in contact with the optical touch screen, the optical stylus converts a portion of an infrared light source into visible light using a fluorescent substance, and then the optical touch screen detects the infrared light and the visible light to locate a contact position of the optical stylus.

Preferably, the optical touch screen includes at least a first glass layer provided with a color filter, a second glass layer provided with a thin film transistor, liquid crystal molecules, and an optical sensor. Further, infrared light and visible light are detected using an optical sensor. And, the light emitted by the infrared light source is directed to the optical stylus or propagates in the first glass layer.

Preferably, the optical touch screen includes a waveguide and a plurality of cameras, and the light emitted from the infrared light source propagates in the waveguide.

With the optical touch pen of the present invention, a part of light of the infrared light source can be converted into visible light by the fluorescent substance coated on the surface of the optical touch pen, so that a user does not need to provide power or a battery for the optical touch pen, and the specific position of the touch pen can be determined more accurately after the infrared light and the visible light are received and detected by the camera. In addition, the optical sensor or the camera built in the optical touch screen also provides a faster realization method for the accurate positioning of the touch pen.

Drawings

The various aspects of the present invention will become more apparent to the reader after reading the detailed description of the invention with reference to the attached drawings. Wherein,

FIG. 1 illustrates a first embodiment of a stylus using a camera-based optical touch screen in accordance with an aspect of the present invention, wherein FIG. 1A illustrates a schematic view of an infrared LED light source emitting light to a camera, and FIG. 1B illustrates a schematic view of an infrared LED light source emitting light to a camera when encountering a stylus;

FIG. 2 illustrates a second embodiment of a stylus using an optical touch screen based on an optical waveguide according to yet another aspect of the present invention;

FIG. 3 illustrates a first embodiment of an optical touch panel incorporating in-cell optical sensors, according to yet another aspect of the present invention;

FIG. 4 illustrates a second embodiment of an optical touch panel incorporating in-cell optical sensors, according to yet another aspect of the present invention; and

FIG. 5 is a schematic diagram illustrating the control principle of an optical touch panel using an optical waveguide according to still another aspect of the present invention.

Detailed Description

Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

Before describing several embodiments of the present invention in conjunction with the accompanying drawings, the principle of accurate positioning based on optical touch technology is briefly described. Optical touch technology is a technology different from existing touch principles of infrared, surface acoustic wave, resistance, capacitance, and the like because an optical sensor reacts quickly to a fine motion, making the application of a user lighter, smoother, and simpler. In addition, the CCD optical touch technology breaks the bottleneck of the original touch technology and greatly improves the accuracy, the response speed and the service life. For example, two CCD cameras are installed at the top of the liquid crystal display screen of the user mobile phone and are respectively positioned at the upper left corner and the upper right corner. The CCD camera at the upper left corner emits light through the LED lamp, and the light is reflected by the surrounding reflection strips and enters the CCD camera at the upper right corner; similarly, the CCD camera at the upper right corner emits light through the LED lamp, and the light is reflected and then transmitted into the CCD camera at the upper left corner. Thus, the densely packed light forms a network of light rays in the touch area, with the space between the multiple reflected light rays being very small (e.g., 1 mm). When a point is touched, an included angle is formed by the emitted light and the received light of the point, two included angles are formed by the CCD cameras at the two ends, the two light and the straight line formed between the two cameras, and according to the geometric principle, the accurate coordinate of the touch point is recorded by the controller, so that touch reaction is realized.

Fig. 1 shows a first embodiment of a stylus when using a camera-based optical touch screen. Fig. 1A shows a schematic diagram of an infrared LED light source emitting light to a camera, and fig. 1B shows a schematic diagram of an infrared LED light source emitting light to a camera when encountering a stylus. It will be understood by those of ordinary skill in the art that the infrared LED light source of fig. 1A and 1B is but one of many types of light sources, but the present invention is not intended to be so limited.

Referring to fig. 1B, when the stylus pen is in contact with the liquid crystal display, the stylus pen coated with a fluorescent substance on a surface thereof converts infrared rays emitted from the infrared LED light source into a wavelength range of visible light, that is, the stylus pen can convert one wavelength into another wavelength. And at the contact position of the touch pen and the liquid crystal display screen, the corresponding area on the liquid crystal display screen can be lightened by utilizing infrared light and excited visible light. It will be appreciated by those skilled in the art that the application of a phosphor to the surface of a stylus is only one exemplary embodiment of the present invention, and that phosphors may be applied to other portions of the stylus as well.

Fig. 2 shows a second embodiment of a stylus for an optical touch screen based on an optical waveguide. In this embodiment, infrared light emitted by the infrared LED light source is transmitted within the waveguide. Similarly, when the stylus is in contact with the touch screen, a portion of the infrared light is converted to excited visible light using fluorescent substances on the surface of the stylus. In the whole process, the touch pen does not need to provide a power supply or a battery, and the lighting function is realized through the excited visible light and the infrared light emitted by the infrared LED.

Fig. 3 shows a first embodiment of an optical touch panel integrated with in-cell optical sensors. As shown in fig. 3, in the optical touch panel, the upper layer is a glass layer provided with a color filter, the lower layer is a glass layer provided with a thin film transistor, and a large number of liquid crystal molecules are distributed between the color filter and the thin film transistor. When light passes through the color filter and is emitted to the thin film transistor through the liquid crystal, the optical sensor detects the light. For example, optical sensors convert an optical signal into a current signal. Referring to fig. 3, when infrared light emitted from an infrared LED encounters a stylus, the stylus, whose surface is coated with a fluorescent substance, converts a portion of the infrared light into excited visible light. Then, another portion of the infrared light and the excited visible light are transmitted through a color filter and detected by an embedded optical sensor. In other words, the optical sensor detects not only infrared light but also excited visible light. And accurately positioning the display area clicked by the stylus through comparison of conversion results of the infrared light and the visible light.

Fig. 4 shows a second embodiment of an optical touch panel integrated with in-cell optical sensors. Referring to fig. 3 and 4, the upper layer of the optical touch panel is a glass layer provided with a color filter, the lower layer is a glass layer provided with a thin film transistor, and liquid crystal molecules are laid in the middle. However, in FIG. 4, the light from the infrared LED source is transmitted only through the color filter glass layer. If the stylus is not clicking anywhere in the display area, infrared light is transmitted in a straight line in the color filter glass layer. When the stylus is used to click on the display area, a portion of the infrared light is reflected at the stylus, and a portion of the infrared light is converted to excited visible light by the fluorescent material on the surface of the stylus. When part of the infrared light and the excited visible light pass through the color filter, the optical sensor detects them. For example, the optical sensor converts infrared light into a first current signal, and the optical sensor converts excited visible light into a second current signal, typically, the first current signal being greater than the second current signal. And the converted current signal is subjected to data processing, so that the specific position of the touch pen in contact with the display area can be accurately positioned.

Fig. 5 shows a control principle diagram of the optical touch panel when the optical waveguide is used. As shown in fig. 5, when the infrared LED light source emits infrared light, the fluorescent substance on the surface of the stylus converts a portion of the infrared light into excited visible light at the location where the stylus contacts the display area. It will be appreciated by those skilled in the art that when a portion of the infrared light and the excited visible light pass through the waveguide to the camera head, the camera head can detect both the intensity of the infrared light and the intensity of the visible light. By using the light intensity comparison result between them, the specific position of the touch pen can be accurately positioned.

Hereinbefore, specific embodiments of the present invention are described with reference to the drawings. However, those skilled in the art will appreciate that various modifications and substitutions can be made to the specific embodiments of the present invention without departing from the spirit and scope of the invention. Such modifications and substitutions are intended to be included within the scope of the present invention as defined by the appended claims.

Claims

1. An optical stylus for a mobile terminal, characterized in that the optical stylus has a fluorescent substance by which a part of light of an infrared light source is converted into visible light.

2. The optical stylus of claim 1, wherein the infrared light source is an LED light source.

3. The optical stylus of claim 2, wherein light emitted by the LED light source is directed towards the optical stylus.

4. The optical stylus of claim 2, wherein light emitted by the LED light source propagates in the waveguide.

5. The optical stylus of claim 1, wherein a camera receives infrared light and visible light to locate a position of the optical stylus in a display area.

6. An optical touch screen for a mobile terminal, wherein when an optical touch pen is in contact with the optical touch screen, the optical touch pen converts a part of an infrared light source into visible light by using a fluorescent substance, and wherein the optical touch screen detects infrared light and visible light to locate a contact position of the optical touch pen.

7. The optical touch screen of claim 6, wherein the optical touch screen comprises at least a first glass layer provided with color filters, a second glass layer provided with thin film transistors, liquid crystal molecules, and optical sensors.

8. The optical touch screen of claim 7, wherein the optical sensor detects the infrared light and visible light.

9. The optical touch screen of claim 7, wherein light emitted by the infrared light source is directed toward the optical stylus or propagates within the first glass layer.

10. The optical touch screen of claim 6, wherein the optical touch screen comprises a waveguide and a plurality of cameras, and wherein the infrared light source emits light that propagates in the waveguide.